The present invention relates to a variable radius segment gear in the form of a circular arc and to a gear mechanism for such a segment gear.
A segment gear in the form of a circular arc corresponds to part of the circumference of an internally or externally toothed spur gear. The transmission ratio between such a segment gear and a gear meshing with the latter is constant or can only be varied within very narrow limits. Variation is possible if the segment gear and the gear are caused to orbit relative to one another around an orbiting axis and the distance between the position of engagement between the segment and the gear on the one hand and the orbiting axis on the other hand is altered. However, in known segment gears of the type mentioned at the outset, this distance alteration can only be performed within very narrow limits, within which the orbiting axis is still close to the center of the circular arc.
It is therefore an object of the invention to create a segment gear in which the radius of curvature of the circular arc can be altered within comparatively wide limits.